//加密、解密算法封装：
function Base64() {
	// private property
	let _keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
	
	this.encode64 = function (input) {
	  let keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
	  let output = "";
	  let chr1, chr2, chr3 = "";
	  let enc1, enc2, enc3, enc4 = "";
	  let i = 0;
	  do {
	    chr1 = input.charCodeAt(i++);
	    chr2 = input.charCodeAt(i++);
	    chr3 = input.charCodeAt(i++);
	    enc1 = chr1 >> 2;
	    enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
	    enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
	    enc4 = chr3 & 63;
	  if (isNaN(chr2)) {
	    enc3 = enc4 = 64;
	  } else if (isNaN(chr3)) {
	    enc4 = 64;
	  }
	  output = output + keyStr.charAt(enc1) + keyStr.charAt(enc2)
	      + keyStr.charAt(enc3) + keyStr.charAt(enc4);
	  chr1 = chr2 = chr3 = "";
	  enc1 = enc2 = enc3 = enc4 = "";
	  } while (i < input.length);
	
	  return output;
	}
}
 
export {
	Base64,
}